As the demand increases for varying types of applications within mobile telecommunications networks, service providers must constantly upgrade their systems in order to reliably provide this expanded functionality. What was once a system designed simply for voice communication has grown into an all-purpose network access point, providing access to a myriad of applications including text messaging, multimedia streaming, and general Internet access. In order to support such applications, providers have built new networks on top of their existing voice networks, leading to a less-than-elegant solution. As seen in second and third generation networks, voice services must be carried over dedicated voice channels and directed toward a circuit-switched core, while other service communications are transmitted according to the Internet Protocol (IP) and directed toward a different, packet-switched core. This led to unique problems regarding application provision, metering and charging, and quality of experience (QoE) assurance.
In an effort to simplify the dual core approach of the second and third generations, the 3rd Generation Partnership Project (3GPP) has recommended a new network scheme it terms “Long Term Evolution” (LTE). In an LTE network, all communications are carried over an IP channel from user equipment (UE) to an all-IP core called the Evolved Packet Core (EPC). The EPC then provides gateway access to other networks while ensuring an acceptable QoE and charging a subscriber for their particular network activity.
The 3GPP generally describes the components of the EPC and their interactions with each other in a number of technical specifications, including the following components: Policy and Charging Rules Function (PCRF) implemented in a Policy and Charging Rules Node (PCRN); Policy and Charging Enforcement Function (PCEF) implemented in a Policy and Charging Enforcement Node (PCEN); and Bearer Binding and Event Reporting Function (BBERF) of the EPC. These specifications further provide some guidance as to how these elements interact in order to provide reliable data services and charge subscribers for use thereof.
Within these communication networks, metering may be used to measure usage of the communication network by subscribers. The PCRF may receive usage reports from the OCS. These usage reports may be used to create rules for controlling the usage of the communication network by the user. The OCS may provide various usage counters for a user. The PCRF may request which of these usage counters are reported. Further, an Sy session may be deleted, but the OCS may not receive such notification. In this situation, the OCS may send a usage report related to the deleted Sy session.